RFID MODULE AND RFID DEVICE

• US 20120325916A1
• Filed: 09/05/2012
• Published: 12/27/2012
• Est. Priority Date: 09/06/2010
• Status: Abandoned Application

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: TANIGUCHI, Katsumi, KATO, Noboru, TSUBAKI, Nobuhito
• Application Number:
  US13/603,627
• Publication Number:
  US 20120325916A1
• Time in Patent Office: Days
• US Class Current: 235/492
• CPC Class Codes: H03H 2001/0085 Multilayer, e.g. LTCC, HTCC, green sheets inside PCB filters H05K
• CPC Class Codes: H03H 7/09 Filters comprising mutual inductance
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H03H 7/425 Balance-balance networks

Abstract

An RFID module includes an RFIC element, a filter circuit, a matching circuit, and a radiating element. The filter circuit and the matching circuit define an RFID device. The filter circuit includes a first inductance element, a second inductance element, and a capacitor. The first inductance element and the second inductance element are of equal inductance, and are strongly magnetically coupled to each other so as to strengthen magnetic fluxes to each other. With this configuration, an RFID module and an RFID device that include a filter circuit to remove harmonic components of the RFIC element but are not large as a whole are constructed.

Claims

1. An RFID module comprising:

an RFIC element including a first input/output terminal and a second input/output terminal;

a filter circuit that removes harmonic components of the RFIC element, the filter circuit including a first inductance element connected to the first input/output terminal, and a second inductance element connected to the second input/output terminal; and

a radiating element connected to the filter circuit;

wherein

the first inductance element and the second inductance element are magnetically coupled to each other.

2. The RFID module according to claim 1, wherein a coupling coefficient between the first inductance element and the second inductance element is greater than or equal to about 0.7.

3. The RFID module according to claim 1, further comprising a matching circuit connected between the filter circuit and the radiating element, the matching circuit including an inductance element and a capacitance element or including an inductance element or a capacitance element.

4. The RFID module according to claim 1, wherein the first inductance element includes a first laminated coil element in which a plurality of loop-shaped conductors are laminated, the second inductance element includes a second laminated coil element in which a plurality of loop-shaped conductors are laminated, and a winding axis of the loop-shaped conductors of the first laminated coil element is substantially aligned with a winding axis of the loop-shaped conductors of the second laminated coil element.

5. The RFID module according to claim 4, wherein the loop-shaped conductors of the first laminated coil element and the loop-shaped conductors of the second laminated coil element are alternately laminated.

6. The RFID module according to claim 1, wherein the first inductance element and the second inductance element are included in a multi-layer substrate including a plurality of magnetic layers laminated on each other.

7. The RFID module according to claim 6, wherein the inductance element or the capacitance element of the matching circuit is mounted on a surface of the multi-layer substrate.

8. The RFID module according to claim 1, further comprising a booster element that is coupled to the radiating element through an electromagnetic field and that receives or transmits a radio signal.

9. The RFID module according to claim 8, wherein the radiating element includes a coil-shaped conductor, and the coil-shaped conductor and the booster element are electromagnetically coupled to each other.

10. The RFID module according to claim 8, wherein the radiating element is included in the multi-layer substrate.

11. An RFID device disposed between an RFIC element and a radiating element, the RFIC element including a first input/output terminal and a second input/output terminal, the RFID device comprising:

a filter circuit that removes harmonic components of the RFIC element, the filter circuit including a first inductance element connected to the first input/output terminal, and a second inductance element connected to the second input/output terminal, wherein the first inductance element and the second inductance element are magnetically coupled to each other.

12. The RFID device according to claim 11, further comprising a matching circuit connected on a side of the filter circuit which adjacent to the radiating element, the matching circuit including an inductance element and a capacitance element or including an inductance element or a capacitance element.